<template>
    <div class="todo-footer">
        <label for="">
            <input type="checkbox" v-model="isCheckAll"/>
        </label>
        <span><span>已完成{{count}}</span>/全部{{todos.length}}</span>
        <button class="btn btn-danger" @click="clearComplatedTodos">清除已完成任务</button>
    </div>
</template>
<script lang="ts">
import { computed, defineComponent } from 'vue'
import { Todo } from '../types/todo'
export default defineComponent({
    name: 'Footer',
    props: {
        todos: {
            type: Array as () => Todo[],
            required: true,
        },
        checkAll: {
            type: Function,
            required: true
        },
        clearComplatedTodos: {
            type: Function,
            required: true
        }
    },
    setup(props) {
        // 已完成
        const count = computed(() => {
            return props.todos.reduce(
                (pre, todo, index) => pre + (todo.isComplated ? 1 : 0),
                0
            )
        })
        const isCheckAll = computed({
            get() {
                return count.value  > 0 && props.todos.length === count.value
            },
            set(val) {
                props.checkAll(val)
            }
        })
        return {
            count,
            isCheckAll
        }
    },
})
</script>
<style scoped>
.todo-footer {
    height: 40px;
    line-height: 40px;
    padding-left: 6px;
    margin-top: 5px;
}
.todo-footer label {
    display: inline-block;
    margin-right: 20px;
    cursor: pointer;
}
.todo-footer label input {
    position: relative;
    top: -1px;
    vertical-align: middle;
    margin-right: 5px;
}
.todo-footer button {
    float: right;
    margin-top: 5px;
}
</style>